The present invention is directed to disk brake devices and, more particularly, to a disk brake rotor with hollow portions.
Disk brake assemblies for bicycles and other vehicles are well known. A typical disk brake assembly comprises a brake disk mounted to a disk support member which, in turn, is mounted to a hub that rotates together with the wheel. A caliper is mounted over the edge of the brake disk, wherein the caliper supports first and second brake pads that straddle the brake disk. During operation, the first and second brake pads frictionally contact opposite sides of the brake disk to stop rotation of the brake disk.
Because of the frictional contact between the brake disk and the first and second brake pads, the brake disk can become extremely hot after repeated and strong application of the brake. Such extreme heat can cause warping of the brake disk, glazing of the braking surfaces, and, in the case of hydraulically-operated disk brakes, boiling of the hydraulic fluid. To prevent such undesirable effects, ventilated brake disk assemblies have been proposed. For example, U.S. Pat. No. 6,079,611 discloses a ventilated brake disk wherein a pair of annular plate members that form the braking surfaces are bonded to a corrugated annular spacing member. While the corrugated spacing member provides good ventilation through the resulting radially-oriented open passages, the resulting structure is heavy. As a result, such a ventilated brake disk may not be as desirable for weight-critical applications such as bicycling, where the added rotating weight decreases cycling efficiency.